Golf Club Head Made Of A Titanium-Based Alloy

ABSTRACT

A golf club head made of a titanium-based alloy is provided. The titanium-based alloy includes: aluminum in an amount of 5.2 wt %; chromium in an amount of 1.0 wt %; iron in an amount of 1.0 wt %; tin in an amount of 1.0 wt %; and a balance of titanium and an unavoidable impurity, based on a total weight of the titanium-based alloy.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a golf club head, more particularly to a golf club head made of a titanium-based alloy.

2. Description of the Related Art

A golf club head made of a titanium-based alloy (such as 6Al-4V Ti alloy, or 6Al-1Mo-1V Ti alloy disclosed in Taiwan patent no. 1227154) is most popular in recent years, since it is provided with good mechanical strength and abrasion resistance, and can satisfy the general requirements of golfers.

However, the conventional titanium-based alloy contains noble metals of vanadium and/or molybdenum, and thus, has a relatively high cost. Therefore, there is a need to find a titanium-based alloy that has a reduced cost while still processing good mechanical strength and abrasion resistance.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a golf club head made of a titanium-based alloy that has good mechanical strength (yield strength, tensile strength and elongation) and that has a reduced cost.

Accordingly, a golf club head of the present invention comprises a titanium-based alloy, which includes:

-   -   aluminum in an amount of 5.2 wt %;     -   chromium in an amount of 1.0 wt %;     -   iron in an amount of 1.0 wt %;     -   tin in an amount of 1.0 wt %; and     -   a balance of titanium and an unavoidable impurity, based on a         total weight of the titanium-based alloy.

Addition of iron and tin into the titanium-based alloy improves formability (flowability) efficiently, and reduces the material cost and the manufacturing cost.

Addition of chromium into the titanium-based alloy increases corrosion resistance and oxidation resistance of the alloy, and further increases hardenability and hot strength of the alloy. Therefore, the titanium-based alloy of the present invention is provided with an improved abrasion resistance.

Addition of aluminum into the titanium-based alloy inhibits grain overgrowth in the alloy and promotes dispersion of oxide and nitride particles, thereby providing the alloy with a small grain size which enhances ductility, workability and toughness of the alloy.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A golf club head according to the preferred embodiment of this invention comprises a titanium-based alloy, which includes: aluminum in an amount of 5.2 wt %; chromium in an amount of 1.0 wt %; iron in an amount of 1.0 wt %; tin in an amount of 1.0 wt %; and a balance of titanium and an unavoidable impurity, based on a total weight of the titanium-based alloy. The unavoidable impurity is in an amount not greater than 0.4 wt %, and includes carbon, hydrogen, oxygen, and nitrogen.

Titanium is a material with properties of lightweight, high hardness, and high strength. Aluminum is a good deoxidizer. Aluminum in the amount of 5.2 wt % in combination with a large amount of titanium in the alloy reduces specific gravity of the titanium-based alloy, and thus, the golf club head made of the titanium-based alloy according to the present invention is lightweight. Moreover, aluminum inhibits the grain overgrowth and promotes dispersion of oxides and nitrides in the alloy. Thus, the grains of the alloy are maintained with a relatively small size, and the ductility, workability and toughness of the alloy are improved.

Chromium increases not only the corrosion resistance and the oxidation resistance of the alloy, but also increases the hardenability and the hot strength of the alloy. When a golf club head is made of the titanium-based alloy according to the present invention that includes chromium in the amount of 1.0 wt %, and when the golf club head as made is subjected to a plating treatment, the golf club head can have greatly improved corrosion resistance and oxidation resistance.

Iron and tin improve the formability (flowability) of the titanium-based alloy and thus enhance workability in subsequent processing steps. Thus, the addition of iron and tin reduces the material cost and the manufacturing cost efficiently.

In order to investigate the properties of the titanium-based alloy of the golf club head according to the present invention, tests were conducted at room temperature with regard to mechanical properties of the titanium-based alloy of this invention. 6Al-4V Ti alloy, and 6Al-1Mo-1V Ti alloy were also tested at room temperature for use as comparative examples. The results are shown in Table 1.

In the experiments of the tests, the titanium-based alloy of this invention was prepared by forming a consumable electrode from a titanium sponge, an aluminum-chromium alloy containing chromium, an aluminum-iron alloy containing iron, and an aluminum-tin alloy containing tin, followed by double melting the consumable electrode through a vacuum melting process under a vacuum lower than 1 Pa. During the second melting, the total amount of carbon, hydrogen, oxygen, and nitrogen contained in the alloy was controlled to be not greater than 0.4 wt %.

TABLE 1 Tensile Yield Example and Comparative strength strength Elongation Examples (MPa) (MPa) (%) Alloy of this invention 950 848 24 (in axial direction) Alloy of this invention 943 853 28 (in radial direction) 6Al-4V Ti alloy 820 738 6 6Al-1Mo-1V Ti alloy 816 799 7.5

The titanium-based alloy of the golf club head of this invention exhibits better tensile strength, yield strength and elongation than the titanium-based alloys of the comparative examples including noble metals. Therefore, the golf club head made of the titanium-based alloy of this invention not only possesses improved mechanical properties but also reduces production costs.

While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements. 

1. A golf club head comprising a titanium-based alloy, which includes: aluminum in an amount of 5.2 wt %; chromium in an amount of 1.0 wt %; iron in an amount of 1.0 wt %; tin in an amount of 1.0 wt %; and a balance of titanium and an unavoidable impurity, based on a total weight of said titanium-based alloy.
 2. The golf club head of claim 1, wherein said unavoidable impurity is in an amount not greater than 0.4 wt %, and includes carbon, hydrogen, oxygen, and nitrogen. 